Compatibility brief
Can Emerald catfish (Brochis) live with Oscar?
Risky. This mix is commonly discouraged for typical setups.
Compatibility score
Profile confidence: medium
How we decideFishori checks adult size and predation risk, behaviour, water requirements and tank needs before giving a verdict.
300L
Combined minimum footprint reference for these two species: about 300L (larger active fish often want more length).
Oscar (about 35cm as an adult) can realistically eat Emerald catfish (Brochis) (about 7cm) once grown. Plan around adult sizes, not shop sizes.
Emerald catfish (Brochis) (peaceful) and Oscar (aggressive) are far apart on aggression — bullying or injury is a common outcome in average community layouts.
Assessment details
Aggression mismatch
Top issueOscar is aggressive, while Emerald catfish (Brochis) is peaceful. The aggressive fish will likely bully or harm the peaceful one.
Oscar may eat Emerald catfish (Brochis)
Oscar (35cm) is predatory and Emerald catfish (Brochis) (7cm) is small enough to be eaten. This pairing is unsafe.
Compatible temperature range
Both fish can comfortably share similar water temperatures.
“Oscar is aggressive, while Emerald catfish (Brochis) is peaceful”
Aggression mismatch
Next steps
Concrete changes, not "research more" filler.
- •Emerald catfish (Brochis) should be kept in a group of at least 5 for best health and behaviour.
- •Oscar reaches ~35cm: tank length and turning room matter more than the litre number. A tall, short tank of the same volume is not equivalent.
Try instead
- →Build a species-only tank for the larger fish, or restock with fish too large to be eaten at adult sizes.
- Seriously Fish. Corydoras splendens
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Corydoras splendens
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Corydoras splendens
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
- Seriously Fish. Astronotus ocellatus
Primary: aquarium size, water chemistry, behaviour, and compatibility (URL verified in upgrade script; recheck if site content changes).
- FishBase. Astronotus ocellatus
Secondary: taxonomy, distribution, and maximum length in nature; cross-check with aquarium import lines and measured tank parameters.
- Wikipedia. Astronotus ocellatus
Secondary: general species context; verify all husbandry numbers against a dedicated aquarium care sheet and your test kit, not a single table row.
- Wikipedia. Astronotus ocellatus (oscar)
Encyclopaedia overview; use specialist aquarium sources for your stock's real temperature/pH/footprint needs.
Try this next
Build the full stocking list with Emerald catfish (Brochis) + Oscar
Plan further
Check each species’ mates list, size the glass, then verify the full stock in the builder. Methodology explains how verdicts are produced.
Individual fish vary in personality. Fishori uses conservative hobby rules. Observe any new introduction closely, feed thoughtfully, and keep a quarantine or backup plan. This is not veterinary advice.
Profile data confidence: high. Checked against several solid care sources that mostly agree.

